As an American tradition spanning 77 years, it is certainly a good excuse to be patriotic.So Katy Perry showed her love for her country when she sported an unusual American flag dress to perform at an event kicking off Fleet Week in New York last night.

The satin frock looked like an asymmetric mini dress on first glance but was revealed in all its glory when the 27-year-old stuck her left arm out on the red carpet.

Stars and stripes: Katy Perry went patriotic in an American flag dress to perform at an event kicking off Fleet Week in New York"

The dress then transformed into the Star-Spangled Banner – and if that wasn’t patriotic enough, the singer also gave a sweet salute.

Fashion statement: Katy kept the rest of her outfit simple as she showed off the full effects of her asymmetric dress;

Patriotic: Katy showed her love for her country further when she gave a sweet salute as she got ready to perform;

Unique style: The frock seemed to be an asymmetric dress before Katy revealed it in all its glory'

The star performed a special show on the Brooklyn waterfront for a group of US sailors, even singing into a microphone decorated with American flag diamantes.

Special performance: Katy sang for a group of sailors to kick off the week in Brooklyn"

Hello sailor: One lucky audience member even got to take to the stage beside Katy, who tried on his hat